A magnetic disk drive such as a hard disk drive (HDD) includes a magnetic head in which an element portion including a reproducing element and a recording element is attached to a slider, and perform reproducing/recording of data in a state that the magnetic head flies over a magnetic disk. In such magnetic disk drive, it is required to reduce the height (hereinafter, referred to as flying height of the element portion) of element portion of the magnetic head in flying state from the magnetic disk for realizing further high recording density.
In Japanese Patent Publication No. 5-20635 (“Patent Document 1”), a magnetic head is proposed, in which a heater is provided in the vicinity of the reproducing element and the recording element, and the periphery of the element portion is displaced from an air-bearing surface which is a surface facing the magnetic disk to the side of the magnetic disk utilizing heat expansion due to heat generation by the heater, thereby adjusting the flying height of the element portion.
In the magnetic head using the above heater, since the heater is formed in the vicinity of the reproducing element and the recording element, the temperature of elements tends to increase and it is difficult to expect good element life. Accordingly, it is required for the magnetic head to vary the flying height of the element portion efficiently with respect to electric power given to the heater so that electric power to be given to the heater will be lower.
A coil is used in the recording element included in the magnetic head, and the coil generates heat by iron loss or copper loss at the time of recording data, therefore, the periphery of the element portion is raised from the air-bearing surface also by the heat expansion caused by the heat generation in the same manner as the case of the heater. However, it is required for the raise occurring at the time of recording not to vary the flying height of the element portion so much.